A solution contains Al3 and Co2 . The addition of 0.3868 L of 1.707 M NaOH results in the complete precipitation of the ions as Al(OH)3 and Co(OH)2 . The total mass of the precipitate is 23.36 g . Find the masses of Al3 and Co2 in the solution.

See Explanation

Explanation:

Number of moles of NaOH = 0.3868 L × 1.707 M = 0.660 moles

Reaction of Al^3+ and OH^-

Al^3+(aq) + 3OH^-(aq) > Al(OH)3(s)

If 1 mole of Al3+ reacts with 3 moles of OH^-

x moles of Al^3+ reacts with 0.660 moles of OH^-

x = 1 × 0.660/3

x= 0.22 moles

Mass of Al^3+ = 0.22 moles × 27 g/mol = 5.94 g of Al^3+

Co^2+(aq) + 2OH^-(aq) > Co(OH)2(s)

1 mole of Co^+ reacts with 2 moles of OH^-

x moles of Co^2+ reacts with 0.660 moles of OH^-

x = 1 × 0.660/2 = 0.33 moles

Mass of Co^2+ = 0.33 moles × 59 g/mol = 19.47 g

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

the formula for the conversion of temperature from degree celsius to kelvin is:

the sample of water at is converted to kelvin temperature by using the above formula as:

on comparing the two samples of water at or we can say that at and at respectively. the difference between the temperatures of two samples of water is:

hence, one can say that the sample of water at is greater than the sample of water at by .